Tumor Immune Profiling to Optimize Clinical Trial Readiness in Basal Cell Nevus Syndrome

摘要 PTCH的胚系突变是基底细胞痣综合征(BCNS)的基础，BCNS也是一种显性遗传性疾病 被称为Gorlin-Goltz综合征，受影响的个体表现出HH信号加速，导致 过度的肿瘤负担，需要多次、昂贵且往往是残缺性的外科手术。此外，BCNS 患者在日光保护区域出现多发性基底细胞癌，表明他们独特的肿瘤易感性。除了 肿瘤内源性HH信号，支持基底细胞自发生长和发展的机制 目前仍不清楚。我们的团队在这些患者身上进行了靶向药物的床边临床试验， 最终导致FDA批准SMO抑制剂(SMOI)vismodegib用于治疗晚期BCC。 尽管有显著的抗肿瘤效果，但SMOI的一个主要挑战是临床上出现了 耐药性和显著的肿瘤复发，以及导致一半或更多患者 停止治疗。我们小组和其他人进行的其他临床前和临床研究清楚地表明 单独抑制HH信号可能是必要的，但不足以永久根除BCC。这表明一个 需要开发新的治疗策略来改善当前SMOI的局限性，以改善治疗 结果。利用我们的基因工程ptch1/-/SKH-1小鼠模型，忠实地概括了 人BCNS BCCs的发病机制，我们已经证明：(I)HH信号促进 Foxp3细胞和增加ptch1缺陷皮肤中的促肿瘤细胞因子和趋化因子；(Ii)SMO抑制 增加CD8细胞和CXCL10/11，参与T细胞募集的趋化因子；以及(Iii)治疗BCC- 携带ptch1/-/SKH-1和抗PD-1抗体的ptch1/-/SKH-1可导致显著的肿瘤消退。这些数据与最近的 报告显示免疫检查点抑制剂(抗CTLA4或抗PD-1)对人BCC的疗效 支持免疫机制在基底细胞癌生长中的作用，并强调联合SMO的潜在效用 和免疫检查点阻断，以减轻肿瘤负担。为了促进未来的多中心、单臂试验 维莫地布与人源化抗PD-1单抗联合治疗BCNS 本申请旨在确定ptch1/-/SKH-1中与BCNS微环境相关的肿瘤免疫相关因子 老鼠。在目标1中，我们将确定免疫细胞群的特征并确定其免疫机制 与HH信号有关，在目标2中，我们将全面定义肿瘤免疫图谱并阐明 免疫学相关性预测Vismodegib和PD-1阻断的抗肿瘤反应。

SUMMARY Germline mutations in PTCH underlie basal cell nevus syndrome (BCNS), a dominantly inherited disorder also known as Gorlin-Goltz syndrome, in which affected individuals manifest accelerated Hh signaling, leading to inordinate tumor burden that requires multiple, costly and often mutilating surgical procedures. Moreover, BCNS patients develop multiple BCCs in sun-protected areas illustrating their unique tumor susceptibility. Except for tumor-intrinsic Hh signaling, mechanisms underpinning the spontaneous growth and development of BCCs remain unclear. Our group has fostered bench-to-bedside clinical trials with targeted agents in these patients, ultimately leading to FDA approval of the SMO inhibitor (SMOi) vismodegib for treatment of advanced BCCs. Despite substantial anti-tumor efficacy, a major challenge with SMOi has been the emergence of clinical resistance and significant tumor recurrence, as well as intolerable side-effects causing half or more patients to discontinue treatment. Additional preclinical and clinical studies from our group and others clearly indicate that Hh signaling inhibition alone may be necessary but insufficient to permanently eradicate BCCs. This indicates a need to develop novel treatment strategies to ameliorate the limitations of current SMOi’s to improve treatment outcomes. Utilizing our genetically engineered Ptch1+/-/SKH-1 mouse model that faithfully recapitulates the pathogenesis of human BCNS BCCs, we have demonstrated that (i) Hh signaling promotes accumulation of FoxP3+ cells and increases pro-tumorigenic cytokines and chemokines in Ptch1-deficient skin; (ii) SMO inhibition increases CD8+ cells and CXCL10/11, chemokines involved in T cell recruitment; and (iii) treatment of BCC- bearing Ptch1+/-/SKH-1 with anti-PD-1 results in significant tumor regression. These data, together with recent reports showing efficacy of immune checkpoint inhibitors (anti-CTLA4 or anti-PD-1) in human BCCs, strongly support the role of immune mechanisms in BCC growth, and underscore the potential utility of combined SMO and immune checkpoint blockade to reduce tumor burden. To facilitate a future multi-center, single-arm trial of combined therapy of vismodegib and nivolumab (humanized monoclonal anti-PD-1 antibody) in BCNS patients, this application aims to define tumor immune correlates relevant to BCNS microenvironments in Ptch1+/-/SKH-1 mice. In Aim 1, we will characterize immune cell populations and determine the immunologic mechanisms relevant to Hh signaling, and in Aim 2, we will comprehensively define tumor immune profiles and elucidate immunologic correlates predictive of anti-tumor responses to vismodegib and PD-1 blockade.